programming chip problems

[rjpohl]

Not sure this is the right place to post, if not please move to correct topic.


having problem programming some ST 27c512 eproms.  I get a error message to check ID.  I know I have the willem set correctly and the chips are new.  Anyone have this problem or know how to correct? 


thanks
Bob

[Ken]

I was thinking maybe putting it at the other end but the diagram shows it where you have it.

[Stayouttadabunker]

Just skip the I.D. check...not needed really


BTW That's an M27c64a chip in there...not a 512...lol

[qbert]

If they are chips from China you get that because they are not "real" SSTs or Amel chips. They still work ok if you skip the ID check like Bunker said.

[rjpohl]

I did have the 512's in there but the pic is of a 27c64a.


the chips are from China!!!


I'll try to program a view (unchecking check ID) and see what happens


thanks
Bob

[edoleu]

You can just uncheck the box next to "Check ID" and it will should work fine.


Ethan

[rjpohl]

I unchecked the "check ID"
checked for "blank" and it showed blank
tried to program and got error, see pic

[Stayouttadabunker]

Only thing I can think of is a bad chip...throw it into the eprom eraser for 15 minutes or longer....depending on the age of the UV lamp (They get weaker) and try burning a different chip.


Before doing that tho, maybe try this chip once more but unchecking the "Verify After" box?


You can just "read" the programmed chip after or later to verify if the checksum number comes up the same.


If the checksum comes up different, then it didn't program correctly.

[Tilt]

That chip is junk.  Not unusual for chinese counterfeit chips.

[rjpohl]

is there a good USA supplier? 

[qbert]

I usually see a 5-8% fallout when using Chinese chips.
Still worth it considering probably a 3 or 4x price difference.

[Tilt]

Not only price, but some are completely obsolete, or obsolete in DIP form factor.   You can't get them from anywhere other than China.  Just order extras and be prepared to throw some in the trash right out of the tube.  Just the way it is.

[qbert]

 

[Stayouttadabunker]

How come we don't use cheap OTP chips? 

I see them at Digi-Key, Mouser, Future, and Jameco for about just over $2 apiece?


Digi-Key....>>>

https://www.digikey.com/en/products/detail/microchip-technology/AT27C512R-45PU/1118862?utm_adgroup=Memory&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Integrated%20Circuits%20%28ICs%29_NEW&utm_term=&utm_content=Memory&gclid=CjwKCAiAiML-BRAAEiwAuWVggkJyeblSVz33Qwhr3Jy--1BohPgPgT2l19_nMq8noFqESmL47Iuc9xoCpSAQAvD_BwE


Mouser...>>>

https://www.mouser.com/ProductDetail/Microchip-Technology-Atmel/AT27C512R-70PU?qs=lURXKZrvvXfxaNMm462qBA%3D%3D&gclid=CjwKCAiAiML-BRAAEiwAuWVggvsU_pAWx_nYgWV6PJMjcBE1tl1vO04MzLcJzMRwG-7iseXIk1465RoC4z8QAvD_BwE

Jameco is over $4 tho with the UV glass....>>>
https://www.jameco.com/z/27C512-10-Major-Brands-IC-27C512-10-EPROM-512K-Bit-100ns-CMOS-Ultraviolet-Erasable-ROM_131959.html?CID=MERCH


Future Electronics...cheapest OTP...>>>


https://www.futurlec.com/Memory/27C512_Datasheet.shtml


These were the best ...electronically erasable no UV light needed but expensive as heck and can't get them in the states anymore...only on the slow boat......>>>

https://www.ebay.com/i/274459160580

[Retro tech repair]

If you know your files are good otp chips are perfectly fine if there is a chance your files are not good or you need to try multiple files otp leads to a lot of wasted money.

[Badbaud]

Wow, I have been pulling out EPROMS from stripped games for years, erasing them and selling them for under $10 a tube and no one is buying them on my website but some people will go all the way to China and roll the dice there instead.

[Stayouttadabunker]

Wow, I have been pulling out EPROMS from stripped games for years, erasing them and selling them for under $10 a tube and no one is buying them on my website but some people will go all the way to China and roll the dice there instead.

I'm sick of China chips! haha

Well why didn't you tell us before?!?!?!! jk

[Retro tech repair]

Wow, I have been pulling out EPROMS from stripped games for years, erasing them and selling them for under $10 a tube and no one is buying them on my website but some people will go all the way to China and roll the dice there instead.

I would only buy china chips as a last resort i have crates of basically all chips except 8meg and 4002 chips. I even have a small hoard of s2000 compatible ss chips

[sixcardmark]

Wow, I have been pulling out EPROMS from stripped games for years, erasing them and selling them for under $10 a tube and no one is buying them on my website but some people will go all the way to China and roll the dice there instead.

Order placed! 

[DB26]

Wow, I have been pulling out EPROMS from stripped games for years, erasing them and selling them for under $10 a tube and no one is buying them on my website but some people will go all the way to China and roll the dice there instead.

Put me down too